Since I can't find system-install-packages I had to file this under anaconda,
which makes some sense because anaconda but both i386 and x86_64 packages on the
machine to start with.

The problem is that if you remove either the i386 or x86_64 version of a package
and try to reinstall it via system-package-installer it tells you that the
package is already installed and it even says it's the other package you are
trying to install down to the arch, for example:

Trying to install the X86_64 package for ImageMagick with the i386 version
already installed reports:

ImageMagick-6.2.8.0-3.fc6.x86_64.rpm is already installed

This works in reverse too when trying to install the i386 version with the
X86_64 version already installed.